1. Technical Field
The present disclosure relates generally to the production of acetaldehyde, and more particularly to apparatus and methods for catalytically converting ethylene to acetaldehyde. More specifically, the disclosure relates to the reduction of mass transfer limitations in apparatus and methods for catalytically converting ethylene to acetaldehyde.
2. Background of the Invention
Acetaldehyde is an important, basic material for production of many organic substances, and its derivatives including many industrially significant products such as acetic acid, acetic esters, and related compounds. Important processes for the commercial production of acetaldehyde have included the acetylene hydration process, the ethanol dehydration process, and the ethylene direct oxidation process. Of these processes, acetylene hydration and ethanol dehydration are no longer used, because large amounts of byproducts are formed, primarily due to the relatively severe reaction conditions required.
In contrast to the above processes, the so-called Wacker's process for producing acetaldehyde employs relatively mild reaction conditions. In Wacker's process, ethylene is used as raw feed material and palladium chloride (Pd(2)Cl2)-cupric chloride (Cu(2)Cl2) is used as a catalyst. Because oxygen has a low solubility in water, conventional practice has been to increase the amount of oxygen dissolved by carrying out the reaction under pressure and temperature conditions of about 10 Kg/cm2 and 100° C. However, when excess dissolved oxygen is released into the gas phase and mixes with ethylene, explosive mixtures can result.
Accordingly, there is a need in the industry for improved processes for the production of acetaldehyde whereby production rates are increased, explosion hazards are reduced, and milder reaction conditions, such as lower temperature and pressure, are commercially feasible.